Stvpoll

------------------

- Fix important bug related to vote transferring.

------------------

- Fix subtle bug in vote transfers, where current votes was not updated for every vote transfer.

------------------

- Fix bug in 0.4.1, where not all elected candidates votes were transferred to next preference.

------------------
Important breaking changes: Result data structure is updated. Import paths changed.

- Rewritten type annotations.
- Rewritten internal data structures, minimizing mutation of data.
- Introducing tiebreak strategies.
- Random tiebreaks not uses a shuffled candidate list, which is reported as part of result.
- Utility to recalculate result from previous polls, using ordered candidate list in randomized tiebreaks.
- STVPollBase class moved from ``__init__.py`` to ``abcs.py``.
- Updated result data structure.

-----------

- Introduce *pedantic_order=False*, to avoid incomplete results when randomization can not affect who is elected.

-----------

- Fixed bug where votes were discarded in select_multiple.
- Scottish STV: Select proposals in order of most votes, when there is no more competition.